A cysteine protease responsible for triggering anaphase by hydrolysing cohesin
Clonal Evolution and Blast Crisis Correlate with Enhanced Proteolytic Activity of Separase in BCR-ABL b3a2 Fusion Type CML under Imatinib Therapy.
Unbalanced (major route) additional cytogenetic aberrations (ACA) in the diagnosis of chronic myeloid leukemia (CML) showed an increase in the risk of progression and shorter survival. In addition, the emerging ACA under imatinib treatment and clonal evolution regarded acceleration features and determine treatment failure in accordance with the European LeukemiaNet (ELN) recommendation.
On the basis of 1151 patients with chronic phase Philadelphia chromosome positive CML random-IV study, we examine recent events, ACA arising under imatinib treatment in connection with p210BCR-ABL breakpoint variants b2a2 and b3a2. We found the ACA preferential acquisition is not balanced in patients with vs b2a2 b3a2 fusion type (ratio: 6.3 vs. 1.6, p = 0.0246) concurring quickly advanced to the blast crisis for b3a2 patients (p = 0.0124).
ESPL1 / Separase, a cysteine endopeptidase, is a key player in chromosome segregation during mitosis. Separase excess and / or hyperactivity have been reported from a variety of cancers and causes defective mitotic spindle, the chromosomes missegregation and aneuploidy. We investigated the influence of p210BCR-ABL breakpoint variants and treatment of imatinib on expression and proteolytic activity of Separase measured by specific fluorogenic assay in CML cell lines (b2a2: KCL-22, BV-173; b3a2: K562, LAMA-84). Despite the decline in protein content Separase up to 5.4-fold increase from Separase activity under imatinib treatment was observed exclusively in b3a2 but not in cell lines b2a2.
Mimic the effect of imatinib on BV-173 and LAMA-84 cells with silencing ESPL1 Separase stimulated proteolytic activity in cell lines of both b3a2 and b2a2. Our data indicate the presence of a feedback mechanism-related types of post- translational fusion Separase stimulates proteolytic activity after therapy-induced decrease in protein levels Separase. This can make b3a2 CML cells more susceptible to aneuploidy and clonal evolution from a common ancestor b2a2 and therefore can explain the results of cytogenetic patients with CML.
Clonal Evolution and Blast Crisis Correlate with Enhanced Proteolytic Activity of Separase in BCR-ABL b3a2 Fusion Type CML under Imatinib Therapy.
Separase Cleaves N-Tail of CENP-A CPAR Related Protein-1 in Meiosis I Metaphase-Anaphase transition in C. elegans.
Epigenetically defined centromere in most eukaryotes by the presence of centromeric chromatin containing histone H3 variant CENP-A. Most species have a single gene that encodes a centromeric histone variant while C. elegans has two: HCP-3 (also known as CeCENP-A) and CPAR-1. Before the replacement RNAi experiments showed that the HCP-3 is a functional isoform dominant, consistent with CPAR-1 does not become detectable in the embryo.
GFP :: CPAR-1 loaded onto meiotic chromosomes in diakinesis and enriched bivalents until meiosis I. Here we show that the CPAR-1 :: GFP signal loss of chromosome segregation precisely coincide with the homologous during anaphase I. The loss of GFP:: CPAR-1 signal reflects the proteolytic cleavage between GFP and histone fold of CPAR-1, as CPAR-1 :: GFP, where GFP fused to the C-terminus of CPAR-1, showed no GFP signal loss.
A focus of the candidates involved separase screen, proteases which initiate anaphase by splitting kleisin subunit of cohesin, in reaction to this division. Examination of the N-terminal tail sequence CPAR-1 expressing separase cleavage site and a mutation of the residues alleged signatures on this site removed cleavage reaction, as visualized by the retention of CPAR-1 :: GFP signal in separating homologous chromosomes in metaphase-anaphase transition of meiosis I.
Description: A polyclonal antibody for detection of Separase phospho Ser801) from Human, Mouse. This Separase phospho Ser801) antibody is for WB , IHC-P, IF, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from human Separase around the phosphorylation site of S801
Description: A polyclonal antibody for detection of Separase phospho Ser801) from Human, Mouse. This Separase phospho Ser801) antibody is for WB , IHC-P, IF, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from human Separase around the phosphorylation site of S801
Description: A polyclonal antibody for detection of Separase phospho Ser801) from Human, Mouse. This Separase phospho Ser801) antibody is for WB , IHC-P, IF, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from human Separase around the phosphorylation site of S801
Description: Stable cohesion between sister chromatids before anaphase and their timely separation during anaphase are critical for chromosome inheritance. In vertebrates| sister chromatid cohesion is released in 2 steps via distinct mechanisms. The first step involves phosphorylation of STAG1 (MIM 604358) or STAG2 (MIM 300826) in the cohesin complex. The second step involves cleavage of the cohesin subunit SCC1 (RAD21; MIM 606462) by ESPL1| or separase| which initiates the final separation of sister chromatids (Sun et al.| 2009
Description: Stable cohesion between sister chromatids before anaphase and their timely separation during anaphase are critical for chromosome inheritance. In vertebrates| sister chromatid cohesion is released in 2 steps via distinct mechanisms. The first step involves phosphorylation of STAG1 (MIM 604358) or STAG2 (MIM 300826) in the cohesin complex. The second step involves cleavage of the cohesin subunit SCC1 (RAD21; MIM 606462) by ESPL1| or separase| which initiates the final separation of sister chromatids (Sun et al.| 2009
Description: Stable cohesion between sister chromatids before anaphase and their timely separation during anaphase are critical for chromosome inheritance. In vertebrates| sister chromatid cohesion is released in 2 steps via distinct mechanisms. The first step involves phosphorylation of STAG1 (MIM 604358) or STAG2 (MIM 300826) in the cohesin complex. The second step involves cleavage of the cohesin subunit SCC1 (RAD21; MIM 606462) by ESPL1| or separase| which initiates the final separation of sister chromatids (Sun et al.| 2009
Description: The SEPARASE (Phospho-Ser801) Cell-Based ELISA Kit is a convenient, lysate-free, high throughput and sensitive assay kit that can monitor SEPARASE (Phospho-Ser801) protein expression profile in cells. The kit can be used for measuring the relative amounts of SEPARASE (Phospho-Ser801) in cultured cells as well as screening for the effects that various treatments, inhibitors (ie. siRNA or chemicals), or activators have on SEPARASE (Phospho-Ser801).
Neither whether or uncleavable CPAR-1 centromere-localized in mitosis and not locally around chromatin, indicating that activity has not been retained in the CPAR centromere-1. Although the function of CPAR-1 and cleavage depends separase that remains to be explained, these efforts reveal new substrate separase and provide in vivo biosensors to monitor activity at the beginning of meiosis I separase anaphase.
